Gas turbine engines are well known internal combustion engines typically used to provide thrust to an aircraft or to provide power for land-based operations. Generally speaking, a gas turbine engine includes a fan, a compressor, a combustor and a turbine arranged in a serial fashion. The fan draws in ambient air as it rotates and moves it to the compressor where the air is compressed or pressurized. The compressed air is then communicated to the combustor where it is mixed with fuel and ignited. The products of the combustion are hot gases which are then directed into the turbine. This causes the airfoils in the turbine to rotate, and as turbine is mounted on the same shaft, or shafts, as the compressor and fan, this causes the compressor and fan to rotate as well. Accordingly, once started, it can be seen that the operation of the engine is self-sustaining in that the combustion of more fuel causes more rotation of the turbine and in turn the compressor and the fan. Moreover, the rotation of the fan, which typically has a diameter many times that of the compressor and the turbine, causes the engine to generate thrust.
In order to increase operational efficiency, and thereby decrease fuel consumption, new gas turbine engine designs require the turbine section casings to operate at greater temperatures than ever before. This means that the casing of new gas turbines must be made of materials that are more resistant to heat than the legacy substances they are substituting. However, the casing must also have sufficient resilience to resist foreign object damage and contain blade liberation. Foreign object damage is a constant concern of the aerospace industry, as any impingement of ice, water, sand, dirt, animals (e.g., birds) and other foreign objects found in the air or on the ramps, taxiways and runways of airports can damage the turbine section of the engine and in turn detrimentally affect thrust generation.
One way to increase resistance to foreign object damage is by increasing the thickness of the casing. However, while increasing the thickness of the casing improves its resilience to foreign object damage, the increased thickness also increases the mass of the engine, and thereby offsets the efficiency gained by operating the engine at elevated temperatures. Thus, while certain gas turbine engine blade containment systems are known, improvements to the aforementioned areas of mass and resilience to foreign object damage are desired, all while maintaining the increased efficiency obtained when operating the engine at increased temperatures.